/**

 * Copyright (c) 2014-present, Facebook, Inc.

 *

 * This source code is licensed under the MIT license found in the

 * LICENSE file in the root directory of this source tree.

 */



var regeneratorRuntime = (function (exports) {

    "use strict";



    var Op = Object.prototype;

    var hasOwn = Op.hasOwnProperty;

    var undefined; // More compressible than void 0.

    var $Symbol = typeof Symbol === "function" ? Symbol : {};

    var iteratorSymbol = $Symbol.iterator || "@@iterator";

    var asyncIteratorSymbol = $Symbol.asyncIterator || "@@asyncIterator";

    var toStringTagSymbol = $Symbol.toStringTag || "@@toStringTag";



    function wrap(innerFn, outerFn, self, tryLocsList) {

        // If outerFn provided and outerFn.prototype is a Generator, then outerFn.prototype instanceof Generator.

        var protoGenerator = outerFn && outerFn.prototype instanceof Generator ? outerFn : Generator;

        var generator = Object.create(protoGenerator.prototype);

        var context = new Context(tryLocsList || []);



        // The ._invoke method unifies the implementations of the .next,

        // .throw, and .return methods.

        generator._invoke = makeInvokeMethod(innerFn, self, context);



        return generator;

    }

    exports.wrap = wrap;



    // Try/catch helper to minimize deoptimizations. Returns a completion

    // record like context.tryEntries[i].completion. This interface could

    // have been (and was previously) designed to take a closure to be

    // invoked without arguments, but in all the cases we care about we

    // already have an existing method we want to call, so there's no need

    // to create a new function object. We can even get away with assuming

    // the method takes exactly one argument, since that happens to be true

    // in every case, so we don't have to touch the arguments object. The

    // only additional allocation required is the completion record, which

    // has a stable shape and so hopefully should be cheap to allocate.

    function tryCatch(fn, obj, arg) {

        try {

            return { type: "normal", arg: fn.call(obj, arg) };

        } catch (err) {

            return { type: "throw", arg: err };

        }

    }



    var GenStateSuspendedStart = "suspendedStart";

    var GenStateSuspendedYield = "suspendedYield";

    var GenStateExecuting = "executing";

    var GenStateCompleted = "completed";



    // Returning this object from the innerFn has the same effect as

    // breaking out of the dispatch switch statement.

    var ContinueSentinel = {};



    // Dummy constructor functions that we use as the .constructor and

    // .constructor.prototype properties for functions that return Generator

    // objects. For full spec compliance, you may wish to configure your

    // minifier not to mangle the names of these two functions.

    function Generator() { }

    function GeneratorFunction() { }

    function GeneratorFunctionPrototype() { }



    // This is a polyfill for %IteratorPrototype% for environments that

    // don't natively support it.

    var IteratorPrototype = {};

    IteratorPrototype[iteratorSymbol] = function () {

        return this;

    };



    var getProto = Object.getPrototypeOf;

    var NativeIteratorPrototype = getProto && getProto(getProto(values([])));

    if (NativeIteratorPrototype &&

        NativeIteratorPrototype !== Op &&

        hasOwn.call(NativeIteratorPrototype, iteratorSymbol)) {

        // This environment has a native %IteratorPrototype%; use it instead

        // of the polyfill.

        IteratorPrototype = NativeIteratorPrototype;

    }



    var Gp = GeneratorFunctionPrototype.prototype =

        Generator.prototype = Object.create(IteratorPrototype);

    GeneratorFunction.prototype = Gp.constructor = GeneratorFunctionPrototype;

    GeneratorFunctionPrototype.constructor = GeneratorFunction;

    GeneratorFunctionPrototype[toStringTagSymbol] =

        GeneratorFunction.displayName = "GeneratorFunction";



    // Helper for defining the .next, .throw, and .return methods of the

    // Iterator interface in terms of a single ._invoke method.

    function defineIteratorMethods(prototype) {

        ["next", "throw", "return"].forEach(function (method) {

            prototype[method] = function (arg) {

                return this._invoke(method, arg);

            };

        });

    }



    exports.isGeneratorFunction = function (genFun) {

        var ctor = typeof genFun === "function" && genFun.constructor;

        return ctor

            ? ctor === GeneratorFunction ||

            // For the native GeneratorFunction constructor, the best we can

            // do is to check its .name property.

            (ctor.displayName || ctor.name) === "GeneratorFunction"

            : false;

    };



    exports.mark = function (genFun) {

        if (Object.setPrototypeOf) {

            Object.setPrototypeOf(genFun, GeneratorFunctionPrototype);

        } else {

            genFun.__proto__ = GeneratorFunctionPrototype;

            if (!(toStringTagSymbol in genFun)) {

                genFun[toStringTagSymbol] = "GeneratorFunction";

            }

        }

        genFun.prototype = Object.create(Gp);

        return genFun;

    };



    // Within the body of any async function, `await x` is transformed to

    // `yield regeneratorRuntime.awrap(x)`, so that the runtime can test

    // `hasOwn.call(value, "__await")` to determine if the yielded value is

    // meant to be awaited.

    exports.awrap = function (arg) {

        return { __await: arg };

    };



    function AsyncIterator(generator) {

        function invoke(method, arg, resolve, reject) {

            var record = tryCatch(generator[method], generator, arg);

            if (record.type === "throw") {

                reject(record.arg);

            } else {

                var result = record.arg;

                var value = result.value;

                if (value &&

                    typeof value === "object" &&

                    hasOwn.call(value, "__await")) {

                    return Promise.resolve(value.__await).then(function (value) {

                        invoke("next", value, resolve, reject);

                    }, function (err) {

                        invoke("throw", err, resolve, reject);

                    });

                }



                return Promise.resolve(value).then(function (unwrapped) {

                    // When a yielded Promise is resolved, its final value becomes

                    // the .value of the Promise<{value,done}> result for the

                    // current iteration.

                    result.value = unwrapped;

                    resolve(result);

                }, function (error) {

                    // If a rejected Promise was yielded, throw the rejection back

                    // into the async generator function so it can be handled there.

                    return invoke("throw", error, resolve, reject);

                });

            }

        }



        var previousPromise;



        function enqueue(method, arg) {

            function callInvokeWithMethodAndArg() {

                return new Promise(function (resolve, reject) {

                    invoke(method, arg, resolve, reject);

                });

            }



            return previousPromise =

                // If enqueue has been called before, then we want to wait until

                // all previous Promises have been resolved before calling invoke,

                // so that results are always delivered in the correct order. If

                // enqueue has not been called before, then it is important to

                // call invoke immediately, without waiting on a callback to fire,

                // so that the async generator function has the opportunity to do

                // any necessary setup in a predictable way. This predictability

                // is why the Promise constructor synchronously invokes its

                // executor callback, and why async functions synchronously

                // execute code before the first await. Since we implement simple

                // async functions in terms of async generators, it is especially

                // important to get this right, even though it requires care.

                previousPromise ? previousPromise.then(

                    callInvokeWithMethodAndArg,

                    // Avoid propagating failures to Promises returned by later

                    // invocations of the iterator.

                    callInvokeWithMethodAndArg

                ) : callInvokeWithMethodAndArg();

        }



        // Define the unified helper method that is used to implement .next,

        // .throw, and .return (see defineIteratorMethods).

        this._invoke = enqueue;

    }



    defineIteratorMethods(AsyncIterator.prototype);

    AsyncIterator.prototype[asyncIteratorSymbol] = function () {

        return this;

    };

    exports.AsyncIterator = AsyncIterator;



    // Note that simple async functions are implemented on top of

    // AsyncIterator objects; they just return a Promise for the value of

    // the final result produced by the iterator.

    exports.async = function (innerFn, outerFn, self, tryLocsList) {

        var iter = new AsyncIterator(

            wrap(innerFn, outerFn, self, tryLocsList)

        );



        return exports.isGeneratorFunction(outerFn)

            ? iter // If outerFn is a generator, return the full iterator.

            : iter.next().then(function (result) {

                return result.done ? result.value : iter.next();

            });

    };



    function makeInvokeMethod(innerFn, self, context) {

        var state = GenStateSuspendedStart;



        return function invoke(method, arg) {

            if (state === GenStateExecuting) {

                throw new Error("Generator is already running");

            }



            if (state === GenStateCompleted) {

                if (method === "throw") {

                    throw arg;

                }



                // Be forgiving, per 25.3.3.3.3 of the spec:

                // https://people.mozilla.org/~jorendorff/es6-draft.html#sec-generatorresume

                return doneResult();

            }



            context.method = method;

            context.arg = arg;



            while (true) {

                var delegate = context.delegate;

                if (delegate) {

                    var delegateResult = maybeInvokeDelegate(delegate, context);

                    if (delegateResult) {

                        if (delegateResult === ContinueSentinel) continue;

                        return delegateResult;

                    }

                }



                if (context.method === "next") {

                    // Setting context._sent for legacy support of Babel's

                    // function.sent implementation.

                    context.sent = context._sent = context.arg;



                } else if (context.method === "throw") {

                    if (state === GenStateSuspendedStart) {

                        state = GenStateCompleted;

                        throw context.arg;

                    }



                    context.dispatchException(context.arg);



                } else if (context.method === "return") {

                    context.abrupt("return", context.arg);

                }



                state = GenStateExecuting;



                var record = tryCatch(innerFn, self, context);

                if (record.type === "normal") {

                    // If an exception is thrown from innerFn, we leave state ===

                    // GenStateExecuting and loop back for another invocation.

                    state = context.done

                        ? GenStateCompleted

                        : GenStateSuspendedYield;



                    if (record.arg === ContinueSentinel) {

                        continue;

                    }



                    return {

                        value: record.arg,

                        done: context.done

                    };



                } else if (record.type === "throw") {

                    state = GenStateCompleted;

                    // Dispatch the exception by looping back around to the

                    // context.dispatchException(context.arg) call above.

                    context.method = "throw";

                    context.arg = record.arg;

                }

            }

        };

    }



    // Call delegate.iterator[context.method](context.arg) and handle the

    // result, either by returning a { value, done } result from the

    // delegate iterator, or by modifying context.method and context.arg,

    // setting context.delegate to null, and returning the ContinueSentinel.

    function maybeInvokeDelegate(delegate, context) {

        var method = delegate.iterator[context.method];

        if (method === undefined) {

            // A .throw or .return when the delegate iterator has no .throw

            // method always terminates the yield* loop.

            context.delegate = null;



            if (context.method === "throw") {

                // Note: ["return"] must be used for ES3 parsing compatibility.

                if (delegate.iterator["return"]) {

                    // If the delegate iterator has a return method, give it a

                    // chance to clean up.

                    context.method = "return";

                    context.arg = undefined;

                    maybeInvokeDelegate(delegate, context);



                    if (context.method === "throw") {

                        // If maybeInvokeDelegate(context) changed context.method from

                        // "return" to "throw", let that override the TypeError below.

                        return ContinueSentinel;

                    }

                }



                context.method = "throw";

                context.arg = new TypeError(

                    "The iterator does not provide a 'throw' method");

            }



            return ContinueSentinel;

        }



        var record = tryCatch(method, delegate.iterator, context.arg);



        if (record.type === "throw") {

            context.method = "throw";

            context.arg = record.arg;

            context.delegate = null;

            return ContinueSentinel;

        }



        var info = record.arg;



        if (!info) {

            context.method = "throw";

            context.arg = new TypeError("iterator result is not an object");

            context.delegate = null;

            return ContinueSentinel;

        }



        if (info.done) {

            // Assign the result of the finished delegate to the temporary

            // variable specified by delegate.resultName (see delegateYield).

            context[delegate.resultName] = info.value;



            // Resume execution at the desired location (see delegateYield).

            context.next = delegate.nextLoc;



            // If context.method was "throw" but the delegate handled the

            // exception, let the outer generator proceed normally. If

            // context.method was "next", forget context.arg since it has been

            // "consumed" by the delegate iterator. If context.method was

            // "return", allow the original .return call to continue in the

            // outer generator.

            if (context.method !== "return") {

                context.method = "next";

                context.arg = undefined;

            }



        } else {

            // Re-yield the result returned by the delegate method.

            return info;

        }



        // The delegate iterator is finished, so forget it and continue with

        // the outer generator.

        context.delegate = null;

        return ContinueSentinel;

    }



    // Define Generator.prototype.{next,throw,return} in terms of the

    // unified ._invoke helper method.

    defineIteratorMethods(Gp);



    Gp[toStringTagSymbol] = "Generator";



    // A Generator should always return itself as the iterator object when the

    // @@iterator function is called on it. Some browsers' implementations of the

    // iterator prototype chain incorrectly implement this, causing the Generator

    // object to not be returned from this call. This ensures that doesn't happen.

    // See https://github.com/facebook/regenerator/issues/274 for more details.

    Gp[iteratorSymbol] = function () {

        return this;

    };



    Gp.toString = function () {

        return "[object Generator]";

    };



    function pushTryEntry(locs) {

        var entry = { tryLoc: locs[0] };



        if (1 in locs) {

            entry.catchLoc = locs[1];

        }



        if (2 in locs) {

            entry.finallyLoc = locs[2];

            entry.afterLoc = locs[3];

        }



        this.tryEntries.push(entry);

    }



    function resetTryEntry(entry) {

        var record = entry.completion || {};

        record.type = "normal";

        delete record.arg;

        entry.completion = record;

    }



    function Context(tryLocsList) {

        // The root entry object (effectively a try statement without a catch

        // or a finally block) gives us a place to store values thrown from

        // locations where there is no enclosing try statement.

        this.tryEntries = [{ tryLoc: "root" }];

        tryLocsList.forEach(pushTryEntry, this);

        this.reset(true);

    }



    exports.keys = function (object) {

        var keys = [];

        for (var key in object) {

            keys.push(key);

        }

        keys.reverse();



        // Rather than returning an object with a next method, we keep

        // things simple and return the next function itself.

        return function next() {

            while (keys.length) {

                var key = keys.pop();

                if (key in object) {

                    next.value = key;

                    next.done = false;

                    return next;

                }

            }



            // To avoid creating an additional object, we just hang the .value

            // and .done properties off the next function object itself. This

            // also ensures that the minifier will not anonymize the function.

            next.done = true;

            return next;

        };

    };



    function values(iterable) {

        if (iterable) {

            var iteratorMethod = iterable[iteratorSymbol];

            if (iteratorMethod) {

                return iteratorMethod.call(iterable);

            }



            if (typeof iterable.next === "function") {

                return iterable;

            }



            if (!isNaN(iterable.length)) {

                var i = -1, next = function next() {

                    while (++i < iterable.length) {

                        if (hasOwn.call(iterable, i)) {

                            next.value = iterable[i];

                            next.done = false;

                            return next;

                        }

                    }



                    next.value = undefined;

                    next.done = true;



                    return next;

                };



                return next.next = next;

            }

        }



        // Return an iterator with no values.

        return { next: doneResult };

    }

    exports.values = values;



    function doneResult() {

        return { value: undefined, done: true };

    }



    Context.prototype = {

        constructor: Context,



        reset: function (skipTempReset) {

            this.prev = 0;

            this.next = 0;

            // Resetting context._sent for legacy support of Babel's

            // function.sent implementation.

            this.sent = this._sent = undefined;

            this.done = false;

            this.delegate = null;



            this.method = "next";

            this.arg = undefined;



            this.tryEntries.forEach(resetTryEntry);



            if (!skipTempReset) {

                for (var name in this) {

                    // Not sure about the optimal order of these conditions:

                    if (name.charAt(0) === "t" &&

                        hasOwn.call(this, name) &&

                        !isNaN(+name.slice(1))) {

                        this[name] = undefined;

                    }

                }

            }

        },



        stop: function () {

            this.done = true;



            var rootEntry = this.tryEntries[0];

            var rootRecord = rootEntry.completion;

            if (rootRecord.type === "throw") {

                throw rootRecord.arg;

            }



            return this.rval;

        },



        dispatchException: function (exception) {

            if (this.done) {

                throw exception;

            }



            var context = this;

            function handle(loc, caught) {

                record.type = "throw";

                record.arg = exception;

                context.next = loc;



                if (caught) {

                    // If the dispatched exception was caught by a catch block,

                    // then let that catch block handle the exception normally.

                    context.method = "next";

                    context.arg = undefined;

                }



                return !!caught;

            }



            for (var i = this.tryEntries.length - 1; i >= 0; --i) {

                var entry = this.tryEntries[i];

                var record = entry.completion;



                if (entry.tryLoc === "root") {

                    // Exception thrown outside of any try block that could handle

                    // it, so set the completion value of the entire function to

                    // throw the exception.

                    return handle("end");

                }



                if (entry.tryLoc <= this.prev) {

                    var hasCatch = hasOwn.call(entry, "catchLoc");

                    var hasFinally = hasOwn.call(entry, "finallyLoc");



                    if (hasCatch && hasFinally) {

                        if (this.prev < entry.catchLoc) {

                            return handle(entry.catchLoc, true);

                        } else if (this.prev < entry.finallyLoc) {

                            return handle(entry.finallyLoc);

                        }



                    } else if (hasCatch) {

                        if (this.prev < entry.catchLoc) {

                            return handle(entry.catchLoc, true);

                        }



                    } else if (hasFinally) {

                        if (this.prev < entry.finallyLoc) {

                            return handle(entry.finallyLoc);

                        }



                    } else {

                        throw new Error("try statement without catch or finally");

                    }

                }

            }

        },



        abrupt: function (type, arg) {

            for (var i = this.tryEntries.length - 1; i >= 0; --i) {

                var entry = this.tryEntries[i];

                if (entry.tryLoc <= this.prev &&

                    hasOwn.call(entry, "finallyLoc") &&

                    this.prev < entry.finallyLoc) {

                    var finallyEntry = entry;

                    break;

                }

            }



            if (finallyEntry &&

                (type === "break" ||

                    type === "continue") &&

                finallyEntry.tryLoc <= arg &&

                arg <= finallyEntry.finallyLoc) {

                // Ignore the finally entry if control is not jumping to a

                // location outside the try/catch block.

                finallyEntry = null;

            }



            var record = finallyEntry ? finallyEntry.completion : {};

            record.type = type;

            record.arg = arg;



            if (finallyEntry) {

                this.method = "next";

                this.next = finallyEntry.finallyLoc;

                return ContinueSentinel;

            }



            return this.complete(record);

        },



        complete: function (record, afterLoc) {

            if (record.type === "throw") {

                throw record.arg;

            }



            if (record.type === "break" ||

                record.type === "continue") {

                this.next = record.arg;

            } else if (record.type === "return") {

                this.rval = this.arg = record.arg;

                this.method = "return";

                this.next = "end";

            } else if (record.type === "normal" && afterLoc) {

                this.next = afterLoc;

            }



            return ContinueSentinel;

        },



        finish: function (finallyLoc) {

            for (var i = this.tryEntries.length - 1; i >= 0; --i) {

                var entry = this.tryEntries[i];

                if (entry.finallyLoc === finallyLoc) {

                    this.complete(entry.completion, entry.afterLoc);

                    resetTryEntry(entry);

                    return ContinueSentinel;

                }

            }

        },



        "catch": function (tryLoc) {

            for (var i = this.tryEntries.length - 1; i >= 0; --i) {

                var entry = this.tryEntries[i];

                if (entry.tryLoc === tryLoc) {

                    var record = entry.completion;

                    if (record.type === "throw") {

                        var thrown = record.arg;

                        resetTryEntry(entry);

                    }

                    return thrown;

                }

            }



            // The context.catch method must only be called with a location

            // argument that corresponds to a known catch block.

            throw new Error("illegal catch attempt");

        },



        delegateYield: function (iterable, resultName, nextLoc) {

            this.delegate = {

                iterator: values(iterable),

                resultName: resultName,

                nextLoc: nextLoc

            };



            if (this.method === "next") {

                // Deliberately forget the last sent value so that we don't

                // accidentally pass it on to the delegate.

                this.arg = undefined;

            }



            return ContinueSentinel;

        }

    };



    // Regardless of whether this script is executing as a CommonJS module

    // or not, return the runtime object so that we can declare the variable

    // regeneratorRuntime in the outer scope, which allows this module to be

    // injected easily by `bin/regenerator --include-runtime script.js`.

    return exports;



}(

    // If this script is executing as a CommonJS module, use module.exports

    // as the regeneratorRuntime namespace. Otherwise create a new empty

    // object. Either way, the resulting object will be used to initialize

    // the regeneratorRuntime variable at the top of this file.

    typeof module === "object" ? module.exports : {}

));